This a revision of an application for an NIMH Small Grant being made under the priority category of a newer less experienced investigator. The general research question is whether sociodemographic patterns in exposure and reaction to daily stresses can explain the well-established relations between sociodemographic variables and distress. Specific questions include: What are the associations between sociodemographic variables (SES, gender, marital and employment status, age) and levels of daily stresses and reactivity to these stresses? Which psychosocial variables (personality, social support, and motivational) explain sociodemographic patterns of exposure and reaction? A daily diary study of a national sample of 1000 adults is proposed. Three main types of information will be obtained using the structured daily diary: Questions about daily stressors, daily psychological distress, and daily physical symptoms. The growing recognition of the influence of daily experiences on health has prompted researchers to turn their attention to the question individual differences in exposure to and emotional reactivity to daily experiences. Although the small number of studies that have been carried out in this area has advanced our understanding of daily stress processes, there are important limitations in these studies that will be addressed in the proposed study. First, previous studies in this area have relied on small and often unrepresentative samples that limit the generalizability of findings. For this reason, the study proposed here would be based on a fairly large and nationally representative sample of adults in the age range of 18 to 65. These individuals would be a representative subsample of a general population survey of midlife development funded by the MacArthur Foundation. Second, previous studies of individual differences in exposure and reactivity to daily events have typically examined only one source of variability, such as personality, to the exclusion of others. The proposed study would correct this problem by utilizing the data collected in the larger MacArthur survey on a wide array of sociodemographic and psychosocial variables to study the determinants of exposure and reactivity to daily stress.